Shaykh Baha' al-Din (also spelled Baha'uddin) Muhammad ibn Husayn al-'Amili was born in Baalbek, Lebanon in 1532. He lived in Jabal Amel in a village called Jebah.

As a child, he came to Iran with his father and completed his studies in Isfahan. Having intended to travel to Mecca in 1570, he visited many Islamic countries including Iraq, Syria and Egypt and after spending four years there, he returned to Iran.

Shaykh Baha' al-Din died in 1621 in Isfahan. His body was buried in Mashhad according to his will.

The exact dates of his birth and death are different on his grave stone and on the ceramic of the walls of the room where he is buried in.[citation needed]

Date of birth:

On the ceramics of the wall: 27 February 1547

On the grave stone: March 1546

Date of death:

On the ceramics of the wall: 30 August 1621

On the grave stone: August 1622

The dates on the wall contain day, month and year, while the dates on the grave stone only contain month and year. The ceramics of the wall are made in 1945. It seems that at that time a research is performed about the exact dates, and, therefore, the information about the day is added to the dates.[citation needed]

According to Bahá'í scholar ‘Abdu’l-Hamíd Ishráq-Khávari, Shaykh Baha' al-Din adopted the pen name (takhallus) 'Baha' after being inspired by words of Shi'a ImamMuhammad al-Baqir (the fifth Imam) and Imam Ja'far al-Sadiq (the sixth Imam), who had stated that the Greatest Name of God was included in either Du'ay-i-Sahar or Du'ay-i-Umm-i-Davud. In the first verse of the Du'ay-i-Sahar, a dawn prayer for the Ramadan, the name "Bahá" appears four times: "Allahumma inni as 'aluka min Bahá' ika bi Abháh va kulla Bahá' ika Bahí".[4] His descendants now live in all over Iran with a major concentration on Isfahan city. The family name of his new generation is "Jabalameli" or "Jabal Ameli" which attributes them to their origin land, which was Jabal Amel. They benefit from an elite reputation in theology, science and medicine.[5]

His interest in the sciences is also apparent by some of his works and treaties, although many of his astronomical treatises are yet to be studied.[1] He probably have written 17 tracts and books on astronomy and related subjects. The following are some his works in astronomy:

Risālah dar ḥall‐i ishkāl‐i ʿuṭārid wa qamar (Treatise on the problems of the Moon and Mercury), on attempting to solve inconsistencies of the Ptolemaic system within the context of Islamic astronomy.

Tashrīḥ al‐aflāk (Anatomy of the celestial spheres), a summary of theoretical astronomy where he affirms the view that supports the positional rotation of the Earth. He was one of Islamic astronomers to advocate the feasibility of the Earth's rotation in the 16th century, independent of Western influences. [1]

Shaykh Baha' al-Din's fame was due to his excellent command of mathematics, architecture and geometry. A number or architectural and engineering designs are attributed to him, but none can be substantiated with sources.[1]

He was the architect of Isfahan's Imam Square, Imam Mosque and Hessar Najaf. He also made a sun clock to the west of the Imam Mosque. There is also no doubt about his mastery of topography. The best instance of this is the directing of the water of the Zayandeh River to different areas of Isfahan. He designed a canal called Zarrin Kamar in Isfahan which is one of Iran's greatest canals. He also determined the direction of Qiblah (prayer direction) from the Naghsh-e-Jahan Square.

He also designed and constructed a furnace for a public bathroom, which still exists in Isfahan, known as Sheikh Bahaei's bathroom. The furnace was warmed by a single candle, which was placed in an enclosure. The candle burned for a long time, warming the bath's water. According to his own instructions, the candle's fire would be put out if the enclosure was ever opened. This happened during the restoration and repair of the building and no one has been able to make the system work again. He also designed the Manar Jonban (shaking minaret), which still exists in Isfahan.

Shaykh Baha' al-Din is also attributed with architectural planning of the city of Isfahan during the Safavid era. Shaykh had designed a public bath called "Garmabeh-e-shaykh" in Isphahan which for a long time it was running and providing hot water to public for years without any visible heating system of the day which usually needed tons of wood. Recently in 1969-70 the bathroom heating system was excavated and few series of underground pipe lines made of sun dried clay were discovered even though there are many theories about the working of this heating system, it was concluded recently that he knew about biogas and the network was to guide toilet wells which were common to Iranian's houses and mosques.

Shaykh Baha' al-Din was also an adept of mysticism. He had a distinct Sufi leaning for which he was criticized by Mohammad Baqer Majlesi.[6] During his travels he dressed like a Dervish[6] and frequented Sufi circles.[6] He also appears in the chain of both the Nurbakhshi and Ni'matullāhī Sufi orders.[6] In the work called "Resāla fi’l-waḥda al-wojūdīya" (Exposition of the concept of Wahdat al-Wujud (Unity of Existences), he states that the Sufis are the true believers,[6] calls for an unbiased assessment of their utterances,[6] and refers to his own mystical experiences.[6] His Persian poetry is also replete with mystical allusions and symbols.[6] At the same time, Shaykh Baha' al-Din calls for strict adherence to the Sharia as a prerequisite for embarking on the Tariqah[6] and did not hold a high view of antinomian mysticism.[6]

Shaykh Baha' al-Din contributed numerous works in philosophy, logic, astronomy and mathematics. His works include over 100 articles, epistles and books. Shaykh Baha' al-Din also composed poems in Persian. His outstanding works in the Persian language are Jame’ Abbasi and two masnavis (rhymed couplets) by the names of "Milk and Sugar" and "Bread and Halva".[citation needed]

His other important work is the Kashkool, which includes stories, news, scientific topics, Persian and Arabicproverbs.

His also wrote Khulāṣat al‐ḥisāb (lit. "Essentials of arithmetic"), an Arabic textbook that became popular throughout the Islamic lands from Egypt to India until the 19th century. It was translated into German in Berlin by G. H. F. Nesselmann and published in 1843. A French translation appeared later 1854.[1]